Recent progress in synthesis and electrochemical analysis of room temperature ionic liquids (ILs) has established the promise of this unique class of materials as electrolytes for next-generation lithium-ion batteries. ILs are organic salts having melting points below 100° C. and generally consist of a bulky cation and an inorganic anion. The large cation size allows for delocalization and screening of charges, resulting in a reduction in the lattice energy and thereby the melting point or glass transition temperature. ILs have unique physicochemical properties, such as negligible vapor pressure, non-flammability, good room-temperature ionic conductivity, a wide electrochemical window, and favorable chemical and thermal stability. These properties are desirable for providing IL-based electrolytes for lithium batteries.
However, there are still safety challenges such as flammability of lithium-ion batteries under abuse conditions or even normal conditions. U.S. Pat. No. 8,697,291 to Zhang et al. teaches the use of an electrolyte composition containing a triazine-based additive, but mentions no use of an ionic liquid. Therefore, there is a need to incorporate a novel ionic liquid with flame retardant capabilities into lithium ion batteries.